基于三阶分析模型的斯特林发动机系统模拟和优化

SIMULATION AND OPTIMIZATION FOR A STIRLING ENGINE BASED ON THIRD-ORDER ANALYSIS MODEL

建立了基于Sage的GPU-3斯特林发动机的三阶分析模型,分析了循环过程中的输出功、效率、p-V图、压降等。结果表明,Sage模型的准确度较高,模拟循环输出功和循环效率的误差分别为12.63%~24.26%和-1.10%~7.98%。回热器是压降、换热量和损最大的部件,压降约为加热器的3倍,冷却器的5倍;换热量约为加热器和冷却器的10倍,循环输出功的70倍;损占整机损的50%以上。分别对不同目数丝网的回热器的长度和直径进行优化,得到的最大循环输出功相比优化前提升了31.1%,且回热器的最大换热量提升了33.9%,最大压降下降了73.5%。在此基础上进一步优化加热器和冷却器,循环输出功最高可提升38.9%。

A third-order model based on Sage is applied to analyze and optimize the GPU-3 Stirling engine,including the indicated power output,thermal efficiency,p-V diagram,pressure drop,amount of heat transfer and exergy loss.The prediction deviation of the model is in the range of 12.63%-24.26%for the indicated power output and in the range of-1.10%-7.98%for the thermal efficiency,respectively.The maximum exergy loss is caused by the regenerator,as well as pressure drop and the amount of heat transfer,among all heat exchanges.The pressure drop in regenerator is^3 and^5 times higher than those of the heater and cooler,respectively.The amount of heat transfer of regenerator is 10 times higher than those of the heater and cooler,respectively,and 70 times higher than the value of indicated power output.It should be noted that the exergy loss in the regenerator takes up over 50%of the total,which indicates that it is necessary to firstly optimize the regenerator.The design parameters of regenerator,including the length,diameter and woven wire screens,are optimized based on the model,aiming to obtain the maximum indicated power output.The results show that the power could be increased by 31.1%when the maximum amount of heat transfer of regenerator is improved by 33.9%and the maximum pressure drop is reduced by 73.5%.The power could be further increased up to 38.9%if the heater and cooler could be improved further.